Type ? to view hotkeys in Google services

A handy little trick that's global to most of Google's core services. Press Shift + / (?) or Ctrl + / to display an overlay containing the hotkeys for the application. To hide it you can repeat the hotkey, press Esc or click off the overlay.

Having an easy to learn shortcut that's common across services is a really nice feature for the power user who wants to learn all of the hotkeys.

Here is the overlay for Drive.